Dan Cortese Joins Cast Of `Single Guy'

WASHINGTON - Dan Cortese, ex-"Melrose Place" star and MTV host, is joining the cast of NBC's "The Single Guy" on six upcoming episodes, playing a swinging single who befriends Johnny (Jonathan Silverman).

Dan had better hurry; the network reportedly plans to pull "Single" after the February sweeps to try a new sitcom in that time period.

Even though "Single" is ranked sixth in the country among all prime-time series so far this season, it's still the worst performer among NBC's dynamite Thursday night lineup. At 8:30 that night it loses about a million homes from its lead-in "Friends" audience and is therefore not nearly as much help as it could be to "Seinfeld" at 9.

"The Single Guy" isn't the only series singing the ratings blues. Overall network viewership is continuing to decline; even the numbers for NBC's "ER" - which has dominated the prime-time ratings this fall - are down 10 percent.

On the other hand, network TV advertising is up 21 percent for the first three quarters of the year, from $8.6 billion for January-September 1995 to $10.5 billion for the same period in 1996.

The addition of two new networks, UPN and WB, and the sterling ad performance of NBC over the 17 days of the Summer Olympics apparently account for a lot of the increase.